Comparison of Methods for Bifenthrin Residues Determination in Fermented Wheat Samples
Poređenje metoda za određivanje ostataka bifentrina u fermentisanim uzorcima žita
View/ Open
Author
Djordjevic, Tijana
Djurovic, Rada
Gajic Umiljendic, Jelena
Keywords
WheatFermentation
Pesticides
Residues
Pšenica
fermentacija
pesticidi
ostaci
Metadata
Show full item recordAbstract
Efficiency of three different sample preparation methods for GC/MS determination
of bifenthrin residues in wheat (Triticum spelta) samples fermented by Lactobacillus
plantarum was tested. The first method was based on a methanol:acetone=1:1 extraction
folowed by a purification on columns containing mixture of aluminium oxide and activated
charcoal slurry-packed and eluted with dichlormethane, the second was based on
methanol:acetone=1:1 extraction folowed by the purification on florisil column and elution
by ethil acetate:acetone=4:1, while the third tested method was based on a combination
of the first two mentioned methods, thus methanol:acetone=1:1 extraction and clean-up
throught columns filled with a mixture of aluminum oxide and activated charcoal slurrypacked
and eluted with ethil acetate:acetone=4:1. The second method was the most effective
for obtaining satisfactory recoveries for bifenthrin in a range of 79-83% for four fortification
levels, with good reproducibility i.e. RSD% in a range of 2.2-7.4%. The chosen method
was further optimized by assessing the optimum volume of elution solvent used during
the clean-up procedures. The highest recovery of 82.1% was obtained after elution with
25 ml of solvent. Overall, two-step extraction with 25 ml of methanol:acetone=1:1 solvent
mix for 30 min, followed by clean-up procedure through a glass column with florisil coupled
with elution with 25 ml of ethyl acetate: acetone=4:1, allows simple, efficient and reliable
GC/MS detection of bifenthrin residues from wheat grain fermented by L. plantarum. Testirane su efikasnosti tri različite metode pripreme uzoraka za određivanje ostataka
bifentrina u uzorcima pšenice (Triticum spelta) fermentisane pomoću Lactobacillus plantarum.
Prva metoda zasnivala se na metanolsko-acetonskoj (1:1) ekstrakciji i prečišćavanju
kroz kolonu punjenu smešom aluminijum-oksida i aktivnog uglja u kombinaciji sa dihlormetanom
kao eluentom, druga se zasnivala na metanolsko-acetonskoj (1:1) ekstrakciji i prečišćavanju
kroz kolonu punjenu florisilom u kombinaciji sa smešom etil-acetata i acetona
(4:1) kao eluentom, dok se treća zasnivala na kombinaciji prve dve, tj. metanolsko-acetonskoj
(1:1) ekstrakciji i prečišćavanju kroz kolonu punjenu smešom aluminijum-oksida i aktivnog
uglja u kombinaciji sa smešom etil-acetata i acetona (4:1) kao eluentom. Pokazalo se
da je druga testirana metoda najefikasnija, pri čemu su dobijeni prinosi bifentrina u opsegu
79-83% za četiri koncentraciona nivoa obogaćivanja, sa RSD% u opsegu 2,2-7,4%. Odabrana
metoda je dodatno optimizovana variranjem različitih zapremina korišćenog eluenta.
Najveći prinos metode postignut je pri zapremini eluenta od 25 ml. Predložena metoda,
bazirana na 30-minutnoj ekstrakciji sa 25 ml smeše metanol:aceton=1:1, prečišćavanju na
florisilskoj koloni i eluiranju sa 25 ml smeše etil-acetat:aceton=4:1, pokazala se kao efikasna,
jednostavna i pouzdana metoda za određivanje ostataka bifentrina u fermentisanom žitnom
supstratu.